The present invention relates to a processing apparatus and method for a pre-process of coating an object to be processed such as an LCD substrate.
Generally, the process of manufacturing a liquid crystal display apparatus employs photolithography used in a semiconductor manufacturing process in order to form, e.g., an ITO (Indium Tin Oxide) thin film or an electrode pattern on an LCD substrate (glass substrate). More specifically, the following series of processes (so-called resist process) are performed. A photoresist film is formed on an LCD substrate having a film to be processed, a circuit pattern or the like is transferred onto this photoresist film, and the photoresist film is partially removed by a developing process.
For example, after the LCD substrate is cleaned by a cleaning apparatus, it is hydrophobically treated by an adhesion apparatus and cooled by a cooling apparatus. Then, a photoresist film, e.g., a photo-sensitive film is applied and formed on the LCD substrate by a resist coating apparatus. After the LCD substrate having the photoresist film is heated and baked (pre-baked) by a heating apparatus, it is exposed by an exposure apparatus to have a predetermined pattern transferred on the photoresist film. After the exposed LCD substrate is developed by a developing apparatus, it is baked (post-baked) to polymerize the photoresist film and enhance adhesion between the LCD substrate and the resist pattern.
The LCD substrate which is subjected to the above processes undergoes various film formation processes before the resist coating process. For this reason, in temporarily storing or conveying the LCD substrate during the process, it is exposed to the outer atmosphere, and particles and organic contaminants may be attached thereto. To remove the particles and organic contaminants, the surface of the LCD substrate is cleaned using a brush and a cleaning solution in a pre-process of the resist process. To enhance adhesion of the resist film to the LCD substrate, an adhesion process is performed.
As a means of removing organic contaminants, there is known a technique of decomposing the organic contaminants by using ozone produced upon irradiation of ultraviolet rays on an object to be processed, e.g., a semiconductor wafer to which the organic contaminants are attached (Jpn. Pat. Appln. KOKOKU Publication No. 4-9373). According to this technique, when an ultraviolet lamp, e.g., a low-pressure mercury lamp is turned on, ultraviolet rays of a mercury resonance line having a wavelength of 254 nm are mainly externally radiated, ultraviolet rays of 185 nm are secondarily radiated, and ultraviolet rays of other wavelengths are slightly radiated. By using this production mechanism, organic contaminants are decomposed. That is, ozone is produced by the ultraviolet rays having a wavelength of 185 nm among these ultraviolet rays, and the ozone is decomposed by the ultraviolet rays having a wavelength of 254 nm to produce oxygen as a generated radical. The oxygen as the generated radical decomposes the organic contaminants and scatters them as a gas.
In the above cleaning process, however, the organic contaminants attached to the LCD substrate cannot be completely removed, and a uniform resist film cannot be formed in the next resist process, resulting in a decrease in yield.
Further, although the organic contaminants can be decomposed and removed in this technique, no implement is provided to effectively use ozone produced from an ultraviolet irradiation means, and the LCD substrate cannot be sufficiently cleaned. In addition, an apparatus, an equipment, and the like, except for the object to be processed, must be prevented from being adversely affected by ozone produced from the ultraviolet irradiation means, and leakage of the ozone outside the apparatus must be prevented.